Umezawa et al. Standards in Genomic Sciences (2016) 11:71 DOI 10.1186/s40793-016-0196-0 SHORT GENOME REPORT Open Access The complete genome sequences of sulfur- oxidizing Gammaproteobacteria Sulfurifustis variabilis skN76T and Sulfuricaulis limicola HA5T Kazuhiro Umezawa, Tomohiro Watanabe, Aya Miura, Hisaya Kojima* and Manabu Fukui Abstract Sulfurifustis variabilis and Sulfuricaulis limicola are autotrophic sulfur-oxidizing bacteria belonging to the family Acidiferrobacteraceae in the order Acidiferrobacterales. The type strains of these species, strain skN76T and strain HA5T, were isolated from lakes in Japan. Here we describe the complete genome sequences of Sulfurifustis variabilis skN76T and Sulfuricaulis limicola HA5T. The genome of Sulfurifustis variabilis skN76T consists of one circular chromosome with size of 4.0 Mbp including 3864 protein-coding sequences. The genome of Sulfuricaulis limicola HA5T is 2.9 Mbp chromosome with 2763 protein-coding sequences. In both genomes, 46 transfer RNA-coding genes and one ribosomal RNA operon were identified. In the genomes, redundancies of the genes involved in sulfur oxidation and inorganic carbon fixation pathways were observed. This is the first report to show the complete genome sequences of bacteria belonging to the order Acidiferrobacterales in the class Gammaproteobacteria. Keywords: Bacteria, Gram-negative, Sulfur-oxidizing bacteria, Acidiferrobacterales, Acidiferrobacteraceae Introduction Here we show the complete genome sequences of Sulfurifustis variabilis skN76T and Sulfuricaulis limicola Sulfurifustis variabilis skN76T and Sulfuricaulis limi- HA5T are gammaproteobacterial sulfur-oxidizing bac- cola HA5T as the first genomes of the order teria isolated from sediments of Lake Mizugaki and Lake Acidiferrobacterales. Harutori, respectively [1, 2]. They both belong to the family Acidiferrobacteraceae in the order Acidiferrobac- terales. In this order, only three species have been iso- Organism information lated in pure culture. They are all chemolithoautotrophs Classification and features and can grow by oxidation of inorganic sulfur com- The cells of Sulfurifustis variabilis skN76T are rod- pounds. Sulfurifustis variabilis and Sulfuricaulis limicola shaped or filamentous form with varying length, and are neutrophilic, whereas the other species, Acidiferro- 0.3–0.5 μm in width (Fig. 1a, Table 1). The cells of bacter thiooxydans, is acidophilic [3]. Taxonomy of Sulfuricaulis limicola HA5T are rod-shaped, 1.2–6.0 μm Acidiferrobacter thiooxydans has been revised several in length and 0.3–0.5 μm in width (Fig. 1b, Table 1). times, and the family Acidiferrobacteraceae and order They are both Gram-stain-negative. Sulfurifustis variabi- Acidiferrobacterales were recently established to accom- lis and Sulfuricaulis limicola belong to the family Acidi- modate the species [1, 3–5]. The members of the family ferrobacteraceae within the class Gammaproteobacteria Acidiferrobacteraceae have been frequently detected in (Fig. 2). They both utilized thiosulfate, tetrathionate and various environments as gene sequences [2, 3, 6]. elemental sulfur as electron donors for chemolithoauto- trophic growth under aerobic conditions [1, 2]. * Correspondence: [email protected] The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Umezawa et al. Standards in Genomic Sciences (2016) 11:71 Page 2 of 8 ab Fig. 1 Phase-contrast micrographs of Sulfurifustis variabilis skN76T (a) and Sulfuricaulis limicola HA5T (b), grown with thiosulfate at 45 and 28 °C, respectively. Bars, 5 μm Table 1 Classification and general features of Sulfurifustis variabilis skN76T and Sulfuricaulis limicola HA5T according to MIGS recommendations MIGS ID Property Sulfurifustis variabilis skN76T Sulfuricaulis limicola HA5T Term Evidence code a Term Evidence code a Classification Domain Bacteria TAS [23] Domain Bacteria TAS [23] Phylum Proteobacteria TAS [24] Phylum Proteobacteria TAS [24] Class Gammaproteobacteria TAS [25] Class Gammaproteobacteria TAS [25] Order Acidiferrobacterales TAS [1] Order Acidiferrobacterales TAS [1] Family Acidiferrobacteraceae TAS [1] Family Acidiferrobacteraceae TAS [1] Genus Sulfurifustis TAS [1] Genus Sulfuricaulis TAS [2] Species Sulfurifustis variabilis TAS [1] Species Sulfuricaulis limicola TAS [2] Type strain skN76 Type strain HA5 Gram stain negative TAS [1] negative TAS [2] Cell shape rod or filaments TAS [1] rod TAS [2] Motility motile TAS [1] not reported Sporulation not reported not reported Temperature range 28–46 °C TAS [1]8–37 °C TAS [2] Optimum temperature 42–45 °C TAS [1]28–32 °C TAS [2] pH range; Optimum 6.3–8.9; 6.8–8.2 TAS [1] 6.1–9.2; unknown TAS [2] Carbon source bicarbonate TAS [1] bicarbonate TAS [2] MIGS-6 Habitat Sediment of a lake TAS [1] Sediment of a lake TAS [2] MIGS-6.3 Salinity <2.6 % NaCl (w/v) TAS [1] <1.2 % NaCl (w/v) TAS [2] MIGS-22 Oxygen requirement aerobic TAS [1] aerobic TAS [2] MIGS-15 Biotic relationship free-living TAS [1] free-living TAS [2] MIGS-14 Pathogenicity non-pathogen NAS non-pathogen NAS MIGS-4 Geographic location Lake Mizugaki, Japan TAS [1] Lake Harutori, Japan TAS [2] MIGS-5 Sample collection November 30, 2010 NAS April 26, 2012 NAS MIGS-4.1 Latitude 35°51.5′ N TAS [26] 42°58.4′ N NAS MIGS-4.2 Longitude 138°30.0′ E TAS [26] 144°23.9′ E NAS MIGS-4.4 Altitude not reported not reported a Evidence codes–IDA Inferred from Direct Assay, TAS Traceable Author Statement (i.e., a direct report exists in the literature), NAS Non-traceable Author Statement (i.e., not directly observed for the living, isolated sample, but based on a generally accepted property for the species, or anecdotal evidence). These evidence codes are from the Gene Ontology project Umezawa et al. Standards in Genomic Sciences (2016) 11:71 Page 3 of 8 Fig. 2 Phylogenetic tree showing the relationships of Sulfurifustis variabilis skN76T and Sulfuricaulis limicola HA5T with other members of the class Gammaproteobacteria based on 16S rRNA gene sequences aligned by using CLUSTAL W. Desulfatitalea tepidiphila S28bFT was used as an outgroup. This tree was reconstructed using 1412 sites with the neighbor-joining method by using MEGA6 [27]. Percentage values of 1000 boot- strap resamplings are shown at nodes; values below 50 % were not shown Genome sequencing information Growth conditions and genomic DNA preparation Genome project history Sulfurifustis variabilis skN76T and Sulfuricaulis limicola Sulfurifustis variabillis skN76T and Sulfuricaulis limicola HA5T were grown with 20 mM thiosulfate as an energy HA5T were selected for sequencing as representatives of source in a bicarbonate-buffered medium previously sulfur-oxidizing bacteria belonging to the order Acidifer- described [1], at 45 and 28 °C, respectively. Genomic robacterales, to reveal characteristics of their genomes. DNA samples were prepared by using Wizard® genomic A summary of the project information is shown in DNA purification kit (Promega, Madison, WI, USA) Table 2. from approximately 0.2 ml (skN76) or 0.1 ml (HA5) of Table 2 Project information MIGS ID Property Sulfurifustis variabilis skN76T Sulfuricaulis limicola HA5T Term Term MIGS 31 Finishing quality Completed Completed MIGS-28 Libraries used 15–20 kb SMRTbellTM library 10–20 kb SMRTbellTM library MIGS 29 Sequencing platforms PacBio RS II PacBio RS II MIGS 31.2 Fold coverage 210 × 142 × MIGS 30 Assemblers RS_HGAP Assembly.2 RS_HGAP Assembly.3 MIGS 32 Gene calling method Microbial Genome Annotation Pipeline Microbial Genome Annotation Pipeline Locus Tag SVA SCL Genbank ID AP014936 AP014879 GenBank Date of Release July 29, 2016 July 29, 2016 BIOPROJECT PRJDB4108 PRJDB3927 MIGS 13 Source Material Identifier DSM 100313 DSM 100373 Project relevance Environmental Environmental Umezawa et al. Standards in Genomic Sciences (2016) 11:71 Page 4 of 8 cell pellets. Amounts of the obtained DNA assessed by and circular chromosome was manually constructed in the spectrophotometry were ca. 270 μg (skN76) and 90 μg same manner. (HA5) respectively, and the UV absorption ratio of 260/ 280 nm was greater than 1.8 in both samples. Genome annotation The genomes were annotated automatically using the Genome sequencing and assembly Microbial Genome Annotation Pipeline [7]. Further manual annotation of the predicted protein-coding The genomic DNA was sheared into approximately 20 kb sequences was performed on the basis of BLASTP using g-TUBE (Covaris, Inc., Woburn, MA, USA). The TM searches against the NCBI nonredundant database. SMRTbell templates were prepared from the fragments TM CDSs were annotated as hypothetical protein-coding using SMRTbell Template Prep Kit 1.0 (Pacific Biosci- genes when they met any of the following four cri- ences, Menlo Park, CA, USA). The size-selected libraries teriainthetophitoftheBLASTPanalysis:(1)E- for sequencing were prepared by using BluePippin (Sage value >1e-8, (2) length coverage